Egyptian rights advocates say another activist opposed to the incumbent military-backed government has died in prison, bringing to 14 the number of such deaths in the North African country.

Human rights activists said Khaled Zahran was pronounced dead on Thursday shortly after admission to a hospital in the central Egyptian city of Asyut, situated 375 kilometers (233 miles) south of the capital, Cairo.

The prisoner, whose health condition had gravely worsened in recent days, died because of lack of medical services, rights activists noted.

The death comes as 37-year-old Ahmed Hamed, father of three children, was pronounced dead on August 21 at a police station in the city of Faiyum, located 100 kilometers (62 miles) southwest of Cairo.

A file photo of Ahmed Hamed, an Egyptian political prisoner who died while in custody on August 21, 2015.

Two days earlier, a 40-year-old man who had been detained on charges of being a Muslim Brotherhood member also passed away in police custody 15 days after his arrest at a hospital in Matariya district in northeastern Cairo

Human rights activists in the Egyptian capital say the man was in a very critical condition due to torture when he was transferred to hospital.

Nearly 300 political prisoners have died in Egyptian detention facilities since the then army chief and current president, Abdel-Fattah el-Sisi, ousted Egypt’s first democratically-elected president, Mohamed Morsi, in a coup in July 2013.

Sisi has launched a brutal crackdown on pro-Morsi protesters and brotherhood members, leading to the killing of hundreds and the arrest and imprisonment of tens of thousands, many of whom have been sentenced to death and long prison terms in mass trials.

On Thursday, three Egyptian courts sentenced 52 pro-Morsi supporters to lengthy prison terms on charges of involvement in violence during anti-government protests.

A military court in Suez, situated 127 kilometers (79 miles) east of Cairo, also sentenced a total of 40 defendants to jail terms ranging from 6 to 15 years. The defendants were indicted over their alleged involvement in torching eight oil trucks in the city back in February.

Six university undergraduates and a graduate were also sentenced to 10 years in jail each by a court in the city of Mansoura, located about 120 kilometers (74 miles) northeast of Cairo.

Moreover, a military court in Egypt’s second largest city of Alexandria found five people guilty of attempting to explode a train as it was en route from the Nile Delta province of Beheira to the capital, and sentenced them to 15 years in prison each.